Concrete is a material landscape architects are all too familiar with. Highways are built with it, downtown depends on it, even features that don’t have concrete as the main focal point will often use it somewhere for structural support.
However, I want to talk about concrete and its aesthetic achievements. Long past are the days when a concrete patio was just a boring slab of stark white cement. Concrete can be natural or sleek, funky or futuristic, the only limit is your imagination!
One of the easiest ways to add visual interest to freshly poured concrete is to add texture.
Broom finish is as straight forward as it sounds. A broom is run along the surface of the concrete to create ridges. The thickness and coarseness of the hairs affects the amount of coarseness added. This can be done straight across or in swirls to create a pattern once dry.
2. Salt Finish
Because salt dissolves in water, if it is sprinkled onto the surface of the concrete when still wet and left to dry impressions will be made in the concrete once water is used to wash it away. This creates a distinctive weathered look that is hard to achieve through other methods. Larger particles of salt will create deeper impressions and you can choose to distribute the salt evenly or unevenly depending on the look you want.
A concrete float is a device used to smooth the surface of the concrete. This is the typical finish you will see on most public projects. A float can be as simple as a small hand tool, a long handle with a float attached, or a power trowel for more industrial projects.
A polished concrete surface is not very typical for outdoor applications, but it is very popular indoors. The process is more labor intensive than the first 3 because the goal is to wipe away imperfections. It involves grinding the concrete down until the surface is even and smooth and then applying sealers and resin to give it a nice shine.
5. Sand Blasted
Sand blasting concrete involves using compressed air to shoot sand at high speeds at the surface once the concrete is already dry. This can help to remove paint or smooth a surface that has experienced years of weathering. However, done over a longer period of time it can create a coarser texture and expose aggregate in the concrete to create a brand new surface.
For this category I’m referring to the addition of materials to concrete that affects the way the surface looks.
6. Exposed Aggregate
Exposed aggregate concrete is created by adding aggregate like gravel, crushed stone, pebbles, glass, shells or even recycled plastic to the concrete and then washing away or using chemicals to remove the top layer (of concrete) to expose the aggregate inside. Exposed aggregate is highly customizable, but is typically associated with a more traditional look when used outdoors. When polished and cut, however, it can make a beautiful modern counter top.
Although the finished look of exposed aggregate is very similar to mosaic the process is slightly different. Mosaic usually involves a more deliberate pattern that needs to be precisely placed after the concrete is poured. It can be created with pebbles, glass, plates, or terra cotta pots. It also requires the use of mortar (essentially a form of concrete without the larger gravel pieces) that is typically used to fill in the spaces after the pattern is set. Then the surface is cleaned, as before, to reveal the beautiful pattern below.
While, arguably, indenting into concrete is also adding texture I decided to single it out as its own category due to some of the unique ways this can be done.
8. Board formed
When pavers, walls, or even pathways are built a wooden form is often used to keep the concrete in place. Once the concrete dries it can inadvertedly take on the pattern of the plywood being used. Eventually, people decided to exaggerate this effect by adding additional wood on the inside of the form to show the wood grain on the surface. The result is both a soft and sophisticated look.
Stamped concrete is concrete that is patterned to look like cobblestones, flagstones, tile or wood using a stamp. This reduces the labor that would have been used to lay individual stones or tiles. Often times color is also added to help in the illusion. Over the past couple of years companies have been constantly improving on the look and believability of their products and it’s gotten so good that it can be hard to tell the difference.
Nowadays concrete doesn’t have to be that boring grey/white color we are all used to. You can get concrete any color of the rainbow using pigments to change the color of the concrete itself, or by staining the outside. Staining is great because it can be applied any time after the concrete is cured and can be reapplied to make your floor look brand new.
So, that’s it! We encourage you to experiment with each of the finishes on this list and don’t be afraid to mix and match. The possibilities are endless.